The Illuminatus! Trilogy is a series of three novels by American writers Robert Shea and Robert Anton Wilson, first published in 1975. The trilogy is a satirical, postmodern, science fiction–influenced adventure story; a drug-, sex-, and magic-laden trek through a number of conspiracy theories, both historical and imaginary, related to the authors' version of the Illuminati. The narrative often switches between third- and first-person perspectives in a nonlinear narrative. It is thematically dense, covering topics like counterculture, numerology, and Discordianism.

Robert Anton Wilson was an American author, futurist, psychologist, and self-described agnostic mystic. Recognized within Discordianism as an Episkopos, pope and saint, Wilson helped publicize Discordianism through his writings and interviews. In 1999 he described his work as an "attempt to break down conditioned associations, to look at the world in a new way, with many models recognized as models or maps, and no one model elevated to the truth". Wilson's goal was "to try to get people into a state of generalized agnosticism, not agnosticism about God alone but agnosticism about everything."